TransformStream.h - mozsearch

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim:set ts=2 sw=2 sts=2 et cindent: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef DOM_STREAMS_TRANSFORMSTREAM_H_

#define DOM_STREAMS_TRANSFORMSTREAM_H_

#include "TransformStreamDefaultController.h"

#include "mozilla/dom/BindingDeclarations.h"

#include "mozilla/dom/QueuingStrategyBinding.h"

#include "mozilla/dom/TransformerBinding.h"

#include "nsCycleCollectionParticipant.h"

#include "nsWrapperCache.h"

namespace mozilla::dom {

class WritableStream;

class ReadableStream;

class UniqueMessagePortId;

class MessagePort;

class TransformerAlgorithmsWrapper;

class TransformStream final : public nsISupports, public nsWrapperCache {

 public:

  NS_DECL_CYCLE_COLLECTING_ISUPPORTS

  NS_DECL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS(TransformStream)

  // https://streams.spec.whatwg.org/#transformstream-set-up

  // Intended to be used by interfaces using GenericTransformStream mixin.

  MOZ_CAN_RUN_SCRIPT static already_AddRefed<TransformStream> CreateGeneric(

      const GlobalObject& aGlobal, TransformerAlgorithmsWrapper& aAlgorithms,

      ErrorResult& aRv);

  // Internal slot accessors

  bool Backpressure() const { return mBackpressure; }

  Promise* BackpressureChangePromise() { return mBackpressureChangePromise; }

  void SetBackpressure(bool aBackpressure);

  MOZ_KNOWN_LIVE TransformStreamDefaultController* Controller() {

    return mController;

  void SetController(TransformStreamDefaultController& aController) {

    MOZ_ASSERT(!mController);

    mController = &aController;

  // [Transferable]

  // https://html.spec.whatwg.org/multipage/structured-data.html#transfer-steps

  MOZ_CAN_RUN_SCRIPT bool Transfer(JSContext* aCx,

                                   UniqueMessagePortId& aPortId1,

                                   UniqueMessagePortId& aPortId2);

  // https://html.spec.whatwg.org/multipage/structured-data.html#transfer-receiving-steps

  static MOZ_CAN_RUN_SCRIPT bool ReceiveTransfer(

      JSContext* aCx, nsIGlobalObject* aGlobal, MessagePort& aPort1,

      MessagePort& aPort2, JS::MutableHandle<JSObject*> aReturnObject);

 protected:

  TransformStream(nsIGlobalObject* aGlobal, ReadableStream* aReadable,

                  WritableStream* aWritable);

  explicit TransformStream(nsIGlobalObject* aGlobal);

  ~TransformStream();

  MOZ_CAN_RUN_SCRIPT void Initialize(

      JSContext* aCx, Promise* aStartPromise, double aWritableHighWaterMark,

      QueuingStrategySize* aWritableSizeAlgorithm,

      double aReadableHighWaterMark,

      QueuingStrategySize* aReadableSizeAlgorithm, ErrorResult& aRv);

 public:

  nsIGlobalObject* GetParentObject() const { return mGlobal; }

  JSObject* WrapObject(JSContext* aCx,

                       JS::Handle<JSObject*> aGivenProto) override;

  // WebIDL methods

  // TODO: Mark as MOZ_CAN_RUN_SCRIPT when IDL constructors can be (bug 1749042)

  MOZ_CAN_RUN_SCRIPT_BOUNDARY static already_AddRefed<TransformStream>

  Constructor(const GlobalObject& aGlobal,

              const Optional<JS::Handle<JSObject*>>& aTransformer,

              const QueuingStrategy& aWritableStrategy,

              const QueuingStrategy& aReadableStrategy, ErrorResult& aRv);

  ReadableStream* Readable() const { return mReadable; }

  WritableStream* Writable() const { return mWritable; }

 private:

  nsCOMPtr<nsIGlobalObject> mGlobal;

  // Internal slots

  // MOZ_KNOWN_LIVE for slots that will never be reassigned

  bool mBackpressure = false;

  RefPtr<Promise> mBackpressureChangePromise;

  RefPtr<TransformStreamDefaultController> mController;

  RefPtr<ReadableStream> mReadable;

  RefPtr<WritableStream> mWritable;

};

namespace streams_abstract {

MOZ_CAN_RUN_SCRIPT void TransformStreamErrorWritableAndUnblockWrite(

    JSContext* aCx, TransformStream* aStream, JS::Handle<JS::Value> aError,

    ErrorResult& aRv);

MOZ_CAN_RUN_SCRIPT void TransformStreamError(JSContext* aCx,

                                             TransformStream* aStream,

                                             JS::Handle<JS::Value> aError,

                                             ErrorResult& aRv);

}  // namespace streams_abstract

}  // namespace mozilla::dom

#endif  // DOM_STREAMS_TRANSFORMSTREAM_H_